I haven't used it extensively so maybe I just didn't notice the rolls involved but the fact that it lasts until a long rest more than makes it not a waste of a spell slot.
If I needed it so I could see invisible enemies, and I didn't see those invisible enemies, then it was wasted. There's no benefit to a long duration if the spell is massively nerfed to the point of uselessness, as being able to
maybe see something invisible
eventually isn't going to be much comfort to you in Act 3 =P
